Square Enix are starting to run out of numbers for the FF series :) This is why they are pushing FFXIII as a "series", with a large number of games coming for it - probably to every platform. This includes the 360, the Wii & the PSP (and definitely the DS).
FFXIII will debut on the PS3, and will probably be ported to the 360 (should be easy to do). And if they do decide to use Unreal Engine for future titles, expect to see more games coming for the 360/PS3.
SQEN are sick of being stuffed around. They are one of the most powerful developers in the world (I rank them third behind Ninty & EA). They will do whatever they need to, to maximise profit... as they should.
The Wii is getting Crystal Chronicles II, Dragon Quest Swords at the least. I'll probably get both (I think DQS could well rock - its a perfect "casual" Wii title).
Also going to see much more connectivity from all platforms (esp. the DS/Wii in Japan), as extra cables are no longer needed - and the chance of driving sales of "both" titles is better (although Pokemon Wii didn't do that well - but then I don't think it deserved to).
I *dont* think the PS3 will take off worldwide... anytime soon. Sales will definitely improve around September, but for Japan especially - which seems close to being Nintendo obsessed - its a tough market for Sony. What big PS3 titles are hitting Japan this year again? No MGS? No FF13? No RE5?